Hi. I've been working on this project for about a year. Now is almost complete.

Basically, I've done two different project:
1. Having a Keyrah board alternative, so I used Arduino board and QMK Keyboard firmware.
2. Some 3D Design for putting a Raspberry Pi inside the C64 case IN A NON DESTRUCTIVE WAY so you can put back your original board.

I've built several options (With or without) w/o original joysticks, w/o RasPI, w/o RasPI Power Supply, RGB LED/Original LED, w/o layout change button, etc.
You can run RetroPie, or just plain VICE emulator, or even Combian.

I wanted to know how many people are interested in getting an old (and maybe broken) C64 and transform it to a mulit-game/multi-platform, so I would share the code and designs.